Photo by Gonzalo Déniz.

As Japan’s nuclear disaster stretched into its second week, traces of radiation from the stricken power plants showed up in several U.S. states, and as far away as Iceland.

With the reactors and uranium fuel rods still proving difficult to bring under control, the disaster could be the “death knell” for nuclear power, some analysts said. Countries around the world — from China to Germany — are taking a closer look at their nuclear plants and plans, while the U.S. intends to complete an initial review of its reactors within three months. Some are still arguing publicly for more nuclear, such as European Union Climate Commissioner Connie Hedegaard and veteran environmental journalist George Monbiot, who wrote the disaster changed his mind and made him pro-nuclear.

Despite the radiation now spread across JapanNew Scientist points out fossil fuels are far deadlier than nuclear power — mainly because of air pollution.

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On thin ice: As the planet has continued heating up, the Arctic ice cap has been shrinking — but not in any straightforward, linear fashion. Scientists have been keeping a close eye on two key features: how big the Arctic sea ice cover is at its minimum in the summer and at its maximum in the winter. The National Snow and Ice Data Center has released its latest numbers on the Arctic sea ice, finding it’s tied with 2005 for the lowest on record. As the Arctic thaws, the U.S. Navy should prepare for a military struggle near the North Pole, the U.S. National Academy of Sciences warned.

CO2 court: In the absence of national regulations for greenhouse-gas emissions in the U.S., states are taking regulation matters into their own hands. Louisiana recently became the first to issue greenhouse-gas permits. Six states, and the city of New York, have banded together to sue power companies over their carbon dioxide emissions on the grounds they’re a public nuisance. The governments have filed a brief with the U.S. Supreme Court, and will present their arguments to the court in April.

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California’s long-standing attempt to create a cap-and-trade system for greenhouse gases suffered a setback when a judge ruled the state must do more studies on alternatives. The decision was triggered by a suit from environmental justice advocates, who said the system would ignore the needs of people who live near polluters.

U.K. Prime Minister David Cameron said, while campaigning last year, he wanted to build the “greenest government ever.” To move toward that goal, the government has just tripled the funding for its new Green Investment Bank — which is aimed at funding renewable energy and clean technologies — to 3 billion pounds ($4.8 billion). Getting the bank up and running is, The Guardian reported, the government’s “biggest environmental test.”

The U.K.’s Carbon Trust, a government-backed company that advises businesses on cutting their greenhouse-gas emissions, had its funding slashed earlier this year — but now it is aiming for a big expansion in its business in the U.S.

Pain at the pump continues: With ongoing conflict in Libya and elsewhere in the Middle East, oil prices have remained above $100 a barrel. Republicans have blamed Democrats for high prices at the pump. But gasoline prices in the U.S. are closely tied to global oil prices, as Sen. Jeff Bingaman (D-N.M.) pointed out in a hearing, so Grist’s David Roberts praised him as the only politician speaking truth about gas prices.

Another reason to hate spam: The world’s biggest botnet — or network of hijacked computers — was taken down recently, cutting the global amount of spam emails by 39 percent. Not only may this have gotten rid of a lot of annoying emails for Viagra and even bogus climate change conference invites, but according to McAfee, this measure also took a big chunk out of spam’s sizeable carbon footprint.

The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University’s Nicholas Institute for Environmental Policy Solutions.